Railway traffic controlling apparatus



April 6, 1943.

L. v. LEWIS RAILWAY TRAFFIC CONTROLLING APPARATUS 7 Sheets-Sheet 1 FiledDec. 6, 1941 92 1AM? 719 9 Z ZWK J22 H125 [mam r012 Q Lloyd Klewllr.

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April 6, 1943. L. v. LEWIS RAILWAY TRAFFIC CONTROLLING APPARATUS 7Sheets-Sheet 5 Filed Dec. 6, 194].

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RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 6, 1941 7 Sheet-Sheet v[[15 drz'ozzzmy.

Patented Apr. 6, 1943 RAILWAY TRAFFIC CONTRGLLING APPARATUS Lloyd V.Lewis, Pittsburgh, Pa., assignor to The Union Switch & Signal Company,Swissvale, Pin, a corporation of Pennsylvania Application December 6,1941, Serial No. 421,865

27 Claims.

My invention relates to railway trafiic controlling apparatus, and moreparticularly, to an interlocking control system for governing themovement of trafiic through a track layout comprising a plurality oftrack sections interconnected by track switches which may be variouslyarranged to form difierent traific routes.

The system of my invention is of the entranceexit route interlockingtype in which the switches and signals for the different traffic routesare governed by the operation of push buttons mounted on a suitablecontrol panel which also includes an illuminated diagram of the tracklayout. A push button is provided for each route end in the tracklayout, and the track switches are operated as required to establish adesired route in response to the successive momentary operation of thetwo push buttons identified with the opposite ends of the route, thesignal at'the entrance end clearing automatically as soon as the routebecomes established.

My invention is an improvement upon that disclosed in my priorapplication for Letters Patent of the United States, Serial No. 252,803,filed January 25, 1939, for Railway trafiic controlling apparatus, andalso upon that disclosed in an application for Letters Patent of theUnited States, Serial No. 310,798, filed December 23, 1939, by Henry S.Young, for Railway traffic controlling apparatus.

One object of my invention is the provision of an improved arrangementof route selecting circuits requiring fewer route relays and a smallernumber of contacts per relay than have been required heretofore insystems of corresponding scope.

A feature of my invention is the provision of improved and relativelysimple arrangements for selection between alternative routes having thesame route ends, and for the provision of through routing in the case ofroutes involving intermediate signals.

Another object of my invention is the provision of an improved controlpanel in which the route buttons and miniature levers for operating thetrack switches individually may be mounted in a row below the trackdiagram to secure a more compact arrangement, and in an improvedarrangement for lighting the lamps of the track diagram. Other objectsand features of my invention will be pointed out as the descriptionproceeds.

I shall describe one form of my invention and shall then point out thenovel features thereof in claims.

Referring to the accompanying drawings, Figs. 1A, 1B and 1C takentogether show the track plan for a typical layout chosen to illustratethe route interlocking system of my invention, together with thecircuits for the entrance relays and route relays associated with theoperators control panel and controlled directly by the operator inestablishing the various routes. Fig. 2 shows the circuits for signalcontrol relays for controlling the signals. Fig. 3 shows the usualsignal indication lamps on the track diagram.

Fig. 10 shows the operators control panel including an illuminatedtrack-diagram corresponding to the track layout and indicates thepreferred location of the route buttons for controlling the circuits ofFigs. 1A to 1G and of miniature switch levers L for operating the trackswitches individually. Fig. ll shows the circuits for the indicationlamps in the tracks of the diagram of Fig. 10.

Referring to Figs. 1A, 1B and 1C, the track layout shown is similar tothat of my prior application hereinbefore referred to, and comprises thetwo main tracks of a double track railroad connected by three crossoverscomprising the pairs of track switches IA and IB, 5A and 5B, and IA andIB, respectively, the lower track being also connected to a siding bysingle switch 3. All of the track switches are in their normal positionsas shown. Train movements over the various trafiic routes through thelayout are governed by .the signals 2, 4, 6, 8, I0 and I2, which signalsare normally at stop, as shown. Signals I and I l) are two-arm signalseach having a main arm such as 4A or IDA for governing high speed trainmovements over the main track in the normal direction, providing thetrack portion extending to the next signal in advance for the samedirection, such as signal 23 or 28, is unoccupied, and also having aslow speed arm such as 4C or IflC which governs train movements overdiverging routes and in addition serves as a call on signal which may becleared to admit a train to an occupied main line route. Signals 2, 6, 8and I2 are slow speed signals which may be cleared provided a properroute is set up but regardless of its occupancy. Signals 2| and 22 aredistant signals for signals 4A and IllA, respectively. Signals 20 to 23,inclusive, are automatic block signals of the usual type and theircontrol circuits have consequently not been shown herein.

The track rails are divided into track sections by the usual insulatedjoints, the upper track including the detector sections IA and 5A, theapproach sections HT and MT and the advance section IB'I'. The lowertrack includes the detector sections AIT, 3T and IT, the approachsections IBT and 2IT and the advance section 4T. Each track section isprovided with the usual track circuit having a track battery as shown,at one end and a track relay TR at the other end, connected across thetrack rails. Each detector section track relay controls a slow pick-upslow release repeating relay TP, while each pair of approach sectiontrack relays controls an approach relay, such as relay 4AR or IUAR.

It will be noted that each relay shown herein is identified by a letteror combination of letters prefixed by the designation of the switch orsignal with which the relay is associated, and that the circuits arearranged in the written circuit form with similar circuits groupedtogether in the same view. The contacts are identified by number, andabove each contact may be found the designation of the relay whichoperates it. The terminals of the usual local source of current forenergizing the relays are designated B and C, referring to the positiveor supply terminal and to the negative or common return terminal,respectively.

Each track switch of Figs. 1A to 1C is arranged to be actuated by apower operated switch machine SM, which may be of the electric motortype, as in the system of my prior application, but preferably, and asshown herein, is of the electropneumatic type, such as is illustrated inthe Coleman Patents Nos. 1,238,888 and 1,238,889, issued September 4,1911, for Railway traffic controlling apparatus. The normal and reversecontrol magnets and the lock magets for the switch machines IA-SM andIB-SM are shown herein in Fig. 6, where they are identified by thereference characters N, R and L, respectively, these being controlled inthe usual manner by a polarized switch control relay IWR. Relay IWR isarranged as in the Young application hereinbefore referred to, so as tobe normally deenergized, becoming energized either in response to theoperation of the route selecting relays for routs over crossover I or inresponse to the operation of the switch lever IL provided for operatingcrossover I individually. Relay IWR is held energized by an associatedlocking relay ILR as long as the route remains set up, and also until atrain which has entered the route has passed over the track switchcontrolled thereby and has vacated the detector track section.

The switch machines SM control polarized switch indication relays WP asin the above-mentioned Patent No. 1,238,889, and each relay WP controlscorrespondence relays NC and RC, relay NC or RC being energized onlywhen the associated relay WP indicates that the switches are locked intheir normal or reverse position, respectively, to correspond with thelast operated position of the control relay WR. Relays WP and WR alsocontrol switch indication relays NWK RC, but are normally deenergized,one or the other being energized only when the associated switch controlrelay WR is picked up.

It is to be understood that the control and indication circuits for theremaining switches are similar to those shown in detail for switches IAand IB, except that in case of the single switch 3 only one switchmachine is required.

Referring now to the route selecting apparatus of Figs. 1A to 1C, a pushbutton P is provided for each signal location or route end, and thetrack switches may be operated as required to establish any route bymomentarily operating the two push buttons identified with the oppositeends of the route, as in the Pelikan Patent No. 2,244,401, granted June3, 1941, for Railway traflic controlling apparatus, and likewise, as inthat patent, the relative order of operation of the two buttonsdetermines the trafiic direction, the button operated first functioningas an entrance button, the signal at the corresponding entrance end ofthe selected route clearing automatically as soon as the route becomesestablished. The relays involved include an entrance stick relay PS foreach button which is picked up in response to the momentary operation ofthe associated button provided the entrance relays for conflicting oropposing routes are in their released positions and also include onenormal and one reverse route relay for each track switch, such as therelays IANE and IRE for switch IA, or the relays IBNW and IRW for switchIB. The arrangement differs from those employed heretofore in systems ofthis character in that a pair of route relays is provided for eachswitch, regardless of whether it is operated singly, like switch 3, oris included in a crossover, like switches IA and IB.

The route relays are controlled by the entrance relays and route buttonsover a novel circuit net,- work of interconnected circuits arranged likethe tracks of the layout to include a two-wire route circuit for eachroute. Each route circuit constitutes a loop extending from a connectionto the supply terminal B of a local source of current at a front contactof the entrance relay for the selectedentrance end of the route to apoint cortresponding to the exit end and thence back to the entranceend, over which the route relays (one for each switch of the route) areenergized in parallel, the relays E being energized over the upper wire,and the relays W over the lower wire of the two-wire circuit. Thecircuits associated with the route button 8P for the intermediate signal8 are somewhat differently arranged and include interlocked directionalrelays for sectionalizing the circuits at that point, these includingthe exit relays BXR and 8X8, used only in setting up routes governintramc from left to right, and the relay 5ANW, used only in setting uproutes from right to left. A relay 8PR is also provided which serves inplace of button 8P to effect through routing.

The route circuits are selected in part by the operation of the routerelays, and the novel mode of operation may be more readily understoodby considering the effect of operating a particular button, such asbutton E, but without tracing the circuits in detail. If this is thefirst button operated, relay 4P8 will pick up, marking point 4 as theentrance point, and energizing a portion of the route circuit for route4-8 to pick up the route relays IRE, SXR and BANE, also energizing aportion of the route circuit for route 4I2 to pick up relays 3NE and'FBNE. The points 8 and and RWK which are repeaters of relays NC and I2are thereby rendered available as alternative exits to be selected bythe operation of button SP or IZP, this being indicated by the lightingof the corresponding exit lamps on the track diagram. The energizedroute relays isolate these route circuits from those for routes havingdiiierent entrance points such as 2 or 6, and also render the entrancerelays controlled by buttons 8P, 1UP and HP non-responsive. If theoperation of button IZP follows that of button 4P, for example, itserves merely to connect the two wires of the circuit for route 4-l2together at their exit end to pick up the remaining route relays .iBNWand IBNW for that route, a front contact of relay SBNW maintaining theconnection after button HP is released, these relays also isolate thecircuit for route 4|2 from those having different exit points, therebyreleasing the relays for route 48. The route relays, energized inparallel over a front contact of the entrance relay 4P8, then includeone for each switch of route 4-! 2, and relay 4PS is held energized inturn over a front contact of the track relay for the first track sectionAIT of the route until a train enters the route, or until button 4P ispulled to cancel the route manually.

The energized route relays efiect the establishment of the selectedroute by governing the switch control relays WR of Fig. 6 in a novelmanner, each switch being operated as soon as the required position isascertained. For example, butthat the switch control relay IWR isenergized 5 normal by relay IANE which picks up in response to theoperation of the entrance button 2P, but when button 4P is operated, therequired position of crossover I is indeterminate and the energizationof relay iWR is not effected until the selected exit button 8? or 52! isoperated. In this manner the number of switches to be operatedsimultaneously is reduced. decreasing the maximum demand upon the powersource and speeding up operation.

When each track switch assumes the required position, the correspondingindication relay NWK or RWK becomes energized, as alread mentioned, andthese relays also serve to isolate the energized route circuit fromthose for conflicting routes, being eiTect-ive after a train has enteredthe route and the route relays consequently are released, to restore theroute circuits to normal, section by section. as the successive sectionsare vacated by the train.

The indication relays NWK and RWK also serve to complete a circuit forthe control relay HR for the signal at the entrance end of the route, assoon as it is fully established.

The circuits for the relays HR. are shown in Fig. 2. Heretofore it hasbeen the practice to include contacts of the route relays in circuits ofthis character in order to require the operation of both the entranceand exit buttons to reestablish a route already occupied by a train.This result is attained without the use of additional contacts asrequired heretofore. by energizing the circuits of Fig. 2 over terminalsIE to i8, inclusive, which extend to correspondingly numbered terminalsof at least one route relay controlled by the exit button has beenpicked up.

Each signal control relay HR, together with the correspondence relays NCand RC of Fig. 6, prepares a circuit for clearing the correspondingsignal, as shown in Fig. 7, but the clearing of the signal is madedependent upon the locking electrically of each switch of the route inthe required position in response to the operation of relay HR. Thesignals, as shown herein, are to be understood to be of the well-knownsearchlight type, each having a mechanism G, such as that of the E. J.Blake Reissue Patent No. 14,940 of August 31, 1920. The mechanisms G foreach interlocked signal, shown in 7. controls the usual back-lockindication relay RGP as shown in Fig. 4 or 5, which is energized whenthe signal indicates stop. The mechanisms for the distant signals 2! and22 control the indication relays 2i RH'GP and 22 RGP which energizedwhen the respective signals indicate either stop or caution.

An approach locking relay AS is provided for each signal, which isnormally energized by the associated indication relay RGP when thesignal is at stop and is released upon the energization of theassociated relay HR prior to the clearing of the signal. Two types ofapproach locking relay circuit are provided; Fig. 4 shows circuitstypical of those used with slow speed signals such as signals 2, 6, 8and I2, and provide for the energization of relay AS at the end of arelatively short time interval after the signal is manually put to stop,measured by the heating period of the thermal relay TE. Fig. 5 showscircuits used with the high speed signals 4 and Ill where a longer timeinterval is required, in which case relay TE picks up an auxiliary stickrelay TES at the end of its heating period, and relay AS picks up at theend of the subsequent cooling period. These circuits are arranged as inthe Vantassel Patent No. 2,198,712, issued April 30. 1940, so as toinsure that relay TE is in its normal condition at the beginning of themeasured time interval.

It is also to be noted that the circuits of Fig. 5 are so arranged thatthe approach locking relay is held energized when the home signals whichcontrol it are at stop, regardless of the condition of the distantsignal, but can be picked up only when the distant signal displays arestrictive indication. This arrangement is claimed in a copendingapplication for Letters Patent oi the United States, Serial No. 417,892,filed November 51941 by R. A. McCann, for Railway trafiic controllingapparatus.

Each approach locking relay AS functions in such a manner that it mustbe released to'per-'" mit the clearing of the associated signal and mustbe picked up to permit the operation of any switch in a route which suchgoverns. Each relay AS, when released. connects the associated signalmechanism to the signal net 0 work circuit of Fig. 7 and also releases aseries of section locking relays ES or WS, shown in Fig.

4, including one for each track section. of the selected route, inaccordance with the usual practice, and the section locking relays thenrelease the switch'locking relays LR of Fig.6. The relays LR uponreleasing, complete hold ng circuits for the associated switch controlrelays WR to lock the switches of the route in the required positions,and byclosing their back contacts in Fig. 7, complete the circuit forthe mechanism G for the signal at the entrance to the route to cause itto indicate clear.

It will be seen that the apparatus employed in the system of myinvention consists largely of relays; these are arranged in two groups.One group includes the relays of Figs. 2 to 5, all the relays of Fig. 6except the relays NWK and RWK, and also includes the call-on stickrelays M308 and IUCOS, the track relays TR and TP, and the approachrelays AR of Figs. 1A and 10, all of which are to be understood to be ofthe standard type generally employed in railway signaling. The secondgroup comprises those relays associated directly with the operatorscontrol panel which are preferably of a smaller type, such as that shownin my Patent No. 1,815,947, granted July 28, 1931, for Electricalrelays, and are mounted in a cabinet adjacent the control panel of Fig.10. The relays of this second group include the entrance and routerelays of Figs. 1A to 10, the indication relays NWK and RWK of Fig. 6,already referred to, and in addition include the section indicationrelays SF of Fig. 8, which as shown in Fig. 11, control the circuits forthe white lamps of the track diagram.

It will be readily apparent that the control panel employed with thesystem of my invention'may be of the type shown in my prior applicationemploying a track diagram with linear light units with the route buttonslocated at the endsof the routes on the track diagram, but analternative arrangement such as is shown herein in Fig. 10 is preferred,as it provides a more compact arrangement and permits a simplificationof the lamp circuits. In Fig. 10 the illuminated indicators K are ofrelatively small dimensions and are preferably of the telephone lamptype such as is shown in my Patent No. 1,897,668, issued February 14,1933, for Lamp receptacles. The route buttons P, and likewise the leversL for operating the switches individually, are shown mounted in a rowbelow the diagram. The latter may be of the miniature type such as shownin my Patent No. 1,887,273, issued November 8, 1932, for Circuitcontrollers.

The lamps of the track diagram are controlled in part by the relays ofeach of the two groups above mentioned, the circuits therefor beingshown in Figs. 9 and 11. For each interlocked signal an indicator GK isprovided on the track diagram, comprising normally dark red and greenlamps, as shown in Fig. 9. The red signal indication lamp becomeslighted in response to the operation of the associated entrance relaywhen a route is to be set up, and this lamp is extinguished and thecorresponding green lamp is lighted when the signal clears in responseto the release of the corresponding indication relay RGP by the signalmechanism, as shown in Fig. 4 or 5. In the case of signal 4A or USA, thesignal will of course remain at stop if a controlling track section inadvance is occupied. In this case the operator may reoperate theentrance button to pick up relay GCOS or IGCOS, interposing a contact ofan interrupter relay CT (Fig. 11) in the lamp circuit to cause theindicator to display a flashing red indication, which changes to aflashing green indication upon the clearing of signal 4C or IOC.

The distant signals 2| and 22 are each provided with an indicator DKcomprising a green lamp which is normally dark but which is controlledby the associated relay RHGP of Fig. so as to become lighted when thesignal indicates proceed.

The tracks of the diagram include a red lamp TK for each detectorsection and an approach lamp AK for each approach section lighted by therelease of the track repeater relays TP and approach relays AR of Figs.1A to IC so as to indicate the occupancy of the corresponding sections,and also include a plurality of white lamps controlled over frontcontacts of the track repeating relays TP which are lighted in differentcombinations to indicate the routes established in response to theoperation of the route relays. These include an exit indicator, such as8K or I2K, for each exit point, a normal and a reverse indication lampsuch as 3NK or BRK for each single switch, two normal and one reverseindication lamps such as IANK, RBNK and IRK for each crossover, togetherwith one or more additional lamps such as 3K optionally included betweenthe indication lamps for widely spaced switches to enable a row oflights to be more readily traced. The operation is such that when anentrance button is operated, the resulting operation of the route relayscauses an exit lamp to be lighted to mark each available exit, lamps BKand IZK for example, in case button 4 is operated. All of these exceptthe one for the exit end of the selected route become extinguished whenthe exit button is operated and the exit lamp for the opposite end ofthat route then becomes lighted. One switch indication lamp for eachswitch of the route becomes lighted in response to the operation of therelay NWK or RWK for the switch as soon as the switch assumes therequired position. Finally, a relay SP of Fig. 8 for each section of theroute is picked up in response to the release of the section lockingrelays of Fig. 3, and these serve to maintain the lighting of the whitelamps for each section of the route until the train enters such sectioneven though the route selector relays are released. The control of thewhite lamps by relays SP serves further to provide an indication of therelease of the approach locking effective when a route is cancelledmanually.

The white lamps RK not only indicate that the switches are lockedreverse when steadily lighted, but they are also controlled over backcontacts of the switch indication relays WP and a contact of aninterrupter relay CT so as to display a flashing indication in case aswitch becomes unlocked or displaced from its last operated position atany time, or if during operation it remains in transit from oneoperating position to another for a sufiicient time for the indicationto be observed.

I shall now describe the operation of the apparatus of my inventionunder different assumed conditions, tracing the circuits in detail. Ishall first assume that the apparatus is in the normal condition asshown in the drawing and that the operator desires to clear signal 4A topass an approaching train over route 4l2.

When the train enters the first approach section IQT, Fig. 1A, the trackrelay ISTR drops and releases the approach relay 4AR, whereupon theapproach indicator 4AK becomes lighted on the track diagram to informthe operator of the approach of the train. 1

Normally all of the indication lamps shown in Fig. 10 are dark, and eachroute button is conditioned to function as an entrance button, asalready mentioned.

To set up route 4-l2, the operator will first operate button 4Pmomentarily to pick up relay 4PS. The pick-up circuit for relay APS maybe traced from terminal B at front contact 25 of track relay AITR,'Fig.1A. contact of button 4P, back contacts I5 and "I6 of relays IRW andIBNW through relay 4PS to terminal C. Relay 4PS picks up and completesits stick circuit which is a branch of the circuit just traced includingthe normally closed pull contact 2'! of button 4? and front contact 28of relay 4P8.

Contact 29 of relay 4PS in Fig. 9 completes the circuit for the red lampof the signal indicator IGK on the track diagram, and contact 30 ofrelay 4PS in Fig. 1A connects terminal B to the upper wire of thetwo-wire route circuit for each route originating at the location ofsignal 4.

It will be seen that the track layout provides two alternative routes4I0, one via I reversed and the other via 5 reversed. Th former is takenas the preferred route 4-H) in order to free the parallel route 6-I2,and the circuits are so arranged that the secondary route 4-H] via 5reversed is normally unavailable. Furthermore, the preferred route 4I6via I reversed includes the intermediate signal 8 and thereforeconstitutes a through route comprising two routes 4-8 and 8I6 inend-to-end relation, and although my apparatus is adapted to providethrough routing for the establishment of such routes by the operation ofthe two end buttons only, it is considered preferable not to employ thatmethod for setting up routes for train movements against the normaldirection of traffic, that is, toward a high signal such as I6, and forthis reason, through routing is provided for route 2-I2 only, and is notprovided for route 2-H] nor for route 4-46 via I reversed. The trackplan shows three routes 4-42, the main line route via I normal and I 7normal, and the two run-around routes via I reversed and I reversed, andvia 5 reversed and I reversed. The main line route 4-I2 is of course thepreferred route and is the only one of the three provided for in thecircuits. Route 4--I2 via I reversed and I reversed, however, can beestablished by setting up the partial routes 4-8 and 8I 2 successively.There are, therefore, normally but two available routes originating atpoint 4; route 4-8, and the main line route 4I 2. The route circuit forrout 4-8 extends from terminal B at contact 36 of relay 4PS over a backcontact of relay iBNW from which point one branch extends over backcontacts of relays INWK and IANE through relay IRE to terminal C. RelayIRE picks up and extends the route circuit over its front contact 3 I,wire 32, back contacts 33 and 34 of relays 5ANW and 8X8 through relay8XR to terminal C. Relay SXR picks up and by closing its contact 35,Fig. 11, lights the exit indicator 8K and also energizes relay 5ANE overa branch of the circuit for relay EPS extending from terminal B atcontact 36 of relay 5TR, Fig. 10, wire 31, back contacts of relays 5RWK,BANW, SRW and ISP, front contact 38 of relay 8XR, back contact 39 ofrelay BPS through relay 5ANE to terminal C. Relay 5ANE picks up and byopening its back contacts in the circuits for relays 5RE and ERWprevents button IIJP from functioning as an exit button to complete theroute circuit for the secondary route 4I6 via 5 reversed. Relay SANEalso opens its back contact I64 in the circuit for relay IOPS to preventbutton I 6P from functioning as an entrance button.

The route circuit for the main line route 4I 2 extends from terminal Bat front contact 36 of relay 4PS over a back contact of relay IRW fromwhich point a branch extends over back contacts of relays IRWK, 3RWK andSRE through relay 3NE to terminal C. Relay 3NE thus picks up in responseto the operation of relay 4PS and extends the circuit for route 4l2 overits front contact 40, wire 4I, back contacts of relays 5RW and 5RWK,wire 42, back contacts of relays 'IRWK and IRE through relay 'IBNE toterminal C. Relay 3NE also opens back contactsin the circuits for routes6III and 6-l2, thereby. rendering button 6P ineffective. Relay 'IBNEpicks up and extends the circuit for route 4I2 from wire M and the backcontact of relay 5RW over wire 43, front contact 44 of relay IBNE, backcontact 45 of relay IZPS to contact 46 of button I2P. Relay 'IBNE opensits back contact 41 in the pick-up circuit for relay I2PS, therebyconditioning button I2P to function only as an exit button, and closescontact 48, Fig. 11, to light the corresponding exit indicator IZK onthe track diagram.

The operator now presses button I2P, extending the circuit for route 4I2over contact 46 of button I2P, back contacts 49, 50 and 5| of relaysIZPS, IRE and 'IRWK, wire 52, back contacts of relays 5RWK and 5RWthrough relay 5BNW to terminal C. Relay 5BNW picksyup, whereupon buttonI2P may be released, the energized portion of the circuit for route 4I 2now extending from back contact 45 of relay IZPS over front contact 53of relay 5BNW, back contacts 49 and 50 of relays I ZPS and IRE, wire 54,front contact 55 of relay 5BNW, wire 56, back contacts of relays 3RE,3RWK, I RWK and IRW through r lay IBNW to terminal C. Relay 5BNW opensits back contacts in the circuits for relays 5RE and 5RW, and relay IBNWpicks up, opening its back contacts in the circuits for relays IRE andIRW,

whereupon relays IRE, BXR and BANE'release extinguishing the exitindicator 8K. Relay IBNW closes contact 51, Fig, 11, lighting the exitindicator 4K adjacent the entrance end of route 4I2 on the trackdiagram.

It will be seen that the route relays IBNW, 3NE, 5BNW and IBNE, one foreach switch of the route, are now energized in parallel over frontcontact 30 of the entrance relay IPS, and that back contacts of theseroute relays isolate the energized route circuit from those for allconflicting routes.

The switch control relays WR of Fig. 6 are energized in the requireddirection as soon as sufficient route relays have been operated todefine the required switch positions, assuming of course that theassociated locking relays LR are picked up. It will be noted that allroutes terminating at point I2 require crossover 5 to be normal.Accordingly, in Fig. 6 relay 5WR is energized in the normal directionupon the closing of a front contact of relay 5BNW in response to theoperation of button I2P either as an entrance or exit button. Buttons 4Pand IZP jointly determine the required positions of the remainingswitches of the route, and accordingly, relays IWR, SWR and IWR areenergized in the normal direction only when two route relays con-.trolled respectively by the entrance and. exit but-' tons are bothenergized. For example, relays IWR and 3WR in the case being describedare energized over front contacts of relays I BNW and 3NE in series, andrelay IWR is energized over front contacts of relays 5BNW and IBNE inseries, as shown in Fig. 6.

Each relay WR operates the associated switch or switches to normal, ifthey happen to be reversed or if the associated indication relay WP isdeenergized, by energizing the normal magnets N and the lock magnets Lof the associated switch The relays NWK also complete circuits forlighting the normal switch indication lamps on the track diagram, thewhite lamps IBNK, 3NK, SBNK and lBNK becoming lighted in response to theclosing of contacts 58 to Gil of relays INWK, SNWK, SNWK and 'lNWK,respectively, as shown in Fig. 11.

As soon as route 4-l2 is fully established so that each relay NWK isenergized, the signal control relay AHR of Fig. 2 becomes energized overa circuit extending from terminal B at front contact 30 of relay 4PS,Fig. 1A, over the upper wire of the route circuit for route 4l2 asalready traced, that is, over wires 4i and 43 to contact 53 of relayEBNW, Fig. ii), to terminal [8. From terminal is the circuit extends inFig. 2 over a back contact of relay IZPS and over front contacts of eachof the relays NWK and of relay 4P8 through relay 4HR to terminal C.

Relay ll-IR picks up, opening its back contact 62, Fig. 5, to releasethe associated approach looking relay AAS, which relay is normally heldenergized over its stick circuit, like the corresponding relay of the Vantassel patent hereinbefore referred to.

Referring now to the signal circuit network of Fig. '7, it will be seenthat the closing of front contacts 63 and 64 of relay 4BR and of backcontact 65 of relay AAS connects the winding of the mechanism GAG forsignal 4A to a signal circuit corresponding to route 4l2 which, as maybe traced from the drawing, extends to terminal B at front contact 66 ofrelay IZAS associated with the opposing signal 12, and to terminal C atcontact 64 of relay dHR, but which is now open at back contacts I26 toI30 of the relays LR. In Fig. 3, relay GAS opens contact til, releasingthe section locking relay AlES for the first section AIT of route 4l2,and relay AIES, in turn, by opening contact 63, releases relay 3E8 forsection 3T of the route.

In Fig. 8, relay AIES closes back contact 69, and relay BES closes backcontacts and H, thereby causing the section indication relays AISP, 3SPand ISP to pick up, and in Fig. 11, front contacts of the SP relaysbridge the closed contacts 48, 51, etc., of the route relays to maintainthe white lamps lighted to indicate the route after the route relaysrelease. Lamp 3K is also lighted at this time due to the closing ofcontact 12 of relay 3SP.

In Fig. 6, relay AIES opens its front contact 13, releasing the switchlocking relay ILR, and relay SES opens contacts I24, I25 and I26,thereby releasing relays SLR, SLR and 'ILR, whereupon each relay WR, asshown in detail for relay IWR in Fig. 6, is held energized over itsstick circuit including the back contacts of the associated relay LR,and each relay WR holds the corresponding relay NWK energized providedthe relays WP and NC remain energized, irrespective of the condition ofthe associated route relays. The release of the relays LR effects theclosing of their back contacts I26 to I39 in the signal circuit of Fig.7 above mentioned, thereby effecting the energization of mechanism 4AG.

- This circuit, it will be seen, includes front c0ntacts of the trackrelay for each section between signal 4A and the next signal 23 inadvance, and also includes pole changer contacts of a relay 23H?controlled by that signal, so that signal 4A will display caution orclear, depending upon the position of signal 23, but only if theintervening block is unoccupied. It will be understood that the operatormay set up the route even though it is already occupied, back contact 14of the track repeater relay AITP providing a connection to terminal Bfor energizing relay 4P8 when the first section AIT is occupied, theconnection being reestablished over contact 25 of relay AITR as soon asthis section is vacated.

In the event the route is set up and signal 4A remains at stop, theoperator may clear the callon signal 40 by reoperating the entrancebutton 4P, as in the system of my prior application, to close thepick-up circuit for the call-on stick relay 4COS. As shown in Fig. 1A,this circuit extends from terminal B at contact 25 of relay AITR orcontact 14 of relay AlTP over contact 26 of button 4P, back contact '15of relay IRW, front contacts 1'6 and H of relays lBNW and dRGP, thewinding of relay 4COS, front contact 18 of relay AHR to terminal C.

Relay 4COS picks up and completes its stick circuit at contact 19, andin Fig. 7 relay ACOS completes the energizing circuit for the call-onsignal mechanism 40G at its front contact 80.

The operation of the main signal mechanism 4AG to the caution or clearposition opens its indication contact Y or G, in Fig. 5. The mechanism40G, although of similar construction, is are ranged to be energizedonly in the caution direction to open its contact Y, but in either case,when mechanism tAG or M36: is energized the opening of one of thecontacts mentioned relea es the associated back-lock relay 4RGP, andthis relay in turn opens contact 8| in the circuit for relay 4AS,thereby insuring that relay 4A8 will remain released 'until conditionsare again proper for the operation of the track switches in the routecontrolled by the signal and the signal has again assumed its stopposition.

In Fig. 9, the dropping of contact 82 of relay 4RGP extinguishes the redlamp and lights the green lamp of the signal indication 4GK on the trackdiagram of Fig. 10. With relay 4008 released, as is the case when themain signal is energized, the green lamp is lighted steadily, but withrelay 4COS picked up, a flashing green or red indication is displayeddue to the operation of contact 83 of a continuously operatinginterrupter relay CT shown in Fig. 11.

I shall next assume that the approaching train passes signal 4A or 40and enters section AIT. If this section is not already occupied by apreceding train, relay AiTR will release and the opening of its contact25 will release relay 4P8. However, if relay AITR is already releasedand relay 4P8 is held energized Over back contact 14 of relay AI'I'P, itmay be released manually by pulling button 4? momentarily to opencontact 21.

Relay EPS upon releasing releases the energized route relays and alsorelay 4I-IR, but without sparking at any contact due'to the paths pr0-vided for the inductive discharge of the relays through suitablerectifiers as shown. Signal 4A or 4C will be restored to stop allowingrelay 4RGP to pick up thereby restoring indicator 4GK to its normal darkposition. If the distant signal 2| is properly in its stop or cautionposition, its contact G will be closed and relay 2 IRHGP will beenergized allowing relay 4A8 to pick up over a back contact of the trackrelay AITR shown in Fig. 5. The slow acting track repeater relay AITPwill become deenergized and after a brief time interval will drop itscontact 84, in Fig. 11, extinguishing the white lamps 4K and IBNK andlighting the red lamp AITK on the track diagram to indicate theoccupancy of the first section of route 4I2. Similarly, the release ofrelays STP and ITP as the train enters the succeeding sectionsextinguishes the white lamps and lights the red lamps for these sectionsto register the progress of the train through the route.

When section AIT is vacated relay AiIR picks up reenergizing relay AIESin Fig. 3, and relay AIES reenergizes relay ILR in Fig. 6, therebyreleasing relays IWR and INWK in turn. Relay AIES also releases relayAISP, in Fig. 8, while relay AITR reenergizes the slow pick-up relayAITP which relay is timed to pick up shortly after relay INWK releases,so that when relay AITP picks up the red lamp AITK is extinguished butwithout completing the circuit for any of the white lamps.

It will be seen, therefore, that the locking of crossover I is releasedso that a conflicting route such as route 4B involving only section AITof route 4I2 may be set up as soon as that section is vacated. Similarconsiderations apply to the remaining sections of the route, theapparatus associated with each of these sections being restored tonormal by the passage of the train in a similar manner.

It will next be assumed that the apparatus is in its normal conditionand that buttons AP and 8P are operated to set up route 4-8. Theoperation of button 4P picks up relays 4PS, I RE, SXR and BANE, andrelay 5ANE opens its back contacts in the rout circuit for the secondaryroute 4I0 via 5 reversed as already described. Button SP is conditionedas an exit button by the opening of back contact 85 of relay BXR and theclosing of contact 86 when button 8]? is operated picks up relay BXS,which then establishes a stick circuit at its front contact 34, at thesame time opening the pick-up circuit for relay 8XR, the latter relaybeing held energized over a stick circuit including Contact 81 of button8P until the button is released. Relay BXS closes contact 88 therebyextending the route circuit for route 4-8 over back contact 89 of relaySANW, wire 99, back contact 9| of relay IANE, front contact 92 of relayIRE, back contact I29 of relay IBNW and the lower back contact of relayINWK through relay IRW to terminal C. Relay IRW picks up and opens itsback contacts in the route circuit for route 4-I2, releasing relays 3NEand IBNE, and in Fig. 6 relay IRW completes a circuit over a frontcontact of relay IRE to energize relay iWR in the reverse direction. Thecrossover I is thereby operated to reverse whereupon relays iWP, I'RCand IRWK pick up, and relay 4HR becomes energized over the connection toterminal it. The remaining operations being similar to those alreadydescribed in connection with route 4-I 2, further discussion appearsunnecessary.

Considering next the routes 28, S-IE! and 8-I2, it will be apparent thatif button 2P is operated as an entrance button, relay 2P3 Will be pickedup over the circuit extending over wire 93 to terminal B at contact 84of relay [TR, and then relays IANE, SXR and 5ANE pick up successively.Relay IANE completes the normal circuit for relay IWR in Fig. 6, so thatcrossover I is operated at once. With relay 8XR picked up,

button HP is conditioned as an exit button, as already described, butthere is now another available exit at point i2. Relays ZPS, 8XR andEANE being energized, a branch of the circuit for route 8I2 is closedfrom terminal 13 at contact 36 of relay ETR as already traced over wire3! to front contact 38 of relay SXR, and thence over back contact 39 ofrelay BPS, front contact 95 of relay 5ANE, wire 96, back contact 91 ofrelay lANW, front contact 98 of relay BPS, back contacts of relays lNWKand TBNE through relay IRE to terminal C. Relay IRE picks up and extendsthe circuit from contact 91 over its front contact 89 and back contact45 of relay IZPS to contact 46 of button IZP. Contact I81! of relay IREopens the circuit for relay IZPS, and in Fig. 11 contact Ilil of relayIRE completes the circuit for lighting the exit indicator i2K.

Assuming now that button 8P is operated, relay BXS picks up extendingthe circuit for route 2-8 over its contact 88 to terminal It to preparea circuit for the signal control relay ZHR, thereby completing theselection of route 28. Relays 3XR, EANE and IRE release in response tothe release of button 8?. When relay BXR is released, button EP is againconditioned to serve as an entrance button for routes 8-40 and 3-42, andif it is now operated, a circuit is com.- pleted from terminal B atcontact 35 of relay 5TB over wire 3?, back contacts of relays ERWK andEANW, contact I02 of button 8P, back contact of relay BXR, through relay8P5 to terminal Relay BPS picks up to establish the usual stick circuitand connects terminal B at its front contact 39 to the route circuitsfor routes 8li and 8-Iz2, whereupon relay SANE picks up extending theroute circuit for route 8-42 over its front contact 85, wire B5 andfront contact sea of relay EPS to pick up relay IRE to thereby conditionbutton. I! as an exit button as already described. Similarly, theopening of back contact Hit of relay iiANE? in the circuit for relayIGPS conditions button IBP as an exit butj ton, its lower contact 585being connected to terminal B over contacts 39 and and wire it. RelayFANW or l'RW may now be picked up by the operation of the exit buttonIt? or IZP, respectively, to complete the selection of route 8-iil orii-42, relay Iii-IR becoming energized over the corresponding routecircuit terminal I! or I 8 when the route is established.

Considering next the through route 2-I2,'it has already been pbinted outthat when the entrance button ZP is operated, relays ZPS, IANE.

EANE and ERE become energized, connecting terminal B to contact at ofthe exit button I 2?. The operation of button 12? will extend the routecircuit over back contact 59 of relay IZPS to pick up relay 'iRW as forroute 8-I2, but in the present instance the circuit is further extendedover contact it? of relay lRW, wire ace, back contacts of relays 5RE,5RWK and BPS and front contacts I39 and Ill] of relays 8X3. and 5ANE,through relay SPR to terminal C. Relay GPR picks up and, as will beclear from the drawing, its two lower contacts complete a pick-upcircuit for relay 8XS and a stick circuit for relay tXR the same as whenbutton BP is operated, but in the present instance relay 3PR prepares acircuit closed when relay 8X5 picks up to energize relay 8P8, whereuponrelays @PR and BXR release due to the opening of the lower back contactof relay 3P8. 'I he relays remaining picked up are relays EPS, IANE and8X8 for route 2-8, and relays BPS, ANE, IRE and 'IRW for route 8I 2, thesame as when these routes are set up separately.

A feature of these circuits is that they are so arranged that thethrough routing is rendered inoperative when there is a train in sectionIT approaching signal 8 since under these circumstances it is notdesirable to clear signal 8 by the operation of buttons 2P and IZP. Thisis effected by including a back contact II I of relay ESP in the circuitfor relay 5ANE in Fig. 1B, and by controlling relay ESP over a backcontact of the track relay ITR. as shown in Fig. 8.

It is believed that the route circuits for routes 6I6 and 6--! 2 whichhave a connection to terminal B at front contact I I2 of relay BPSrequire no explanation in view of their similarity to those circuitsalready traced. The circuits for the secondary route 4-? via- 5 reversedmay also-be readily traced, and it will be seen that when relay 4PSpicks up a connection to terminal B at its front contact 30 is extendedover contact 40 of relay 3NE and wire M and a back contact of relay 5ANEthrough relay 5RE to terminal C, provided conditions are such that relaySANE does not respond to the operation of button 4P as hereinbeforedescribed, but remains released. If relay SEE picks up, the circuit isextended over its front contact and wire I66 to contact I65 of buttonIBP, and if button IfiP is operated relay IANW is picked up to furtherextend the circuit over its front contacts H3 and IE4 and wire I I5 topick up relay ERW, and from wire i I5 over contact I16 of relay 5RW andwire 56 to pick up relay IBNW. 4I0 via 5 reversed will be established inresponse to the operation of buttons 4P and IOP, provided relay SANE isprevented from picking up. This will be the case, for example, if route28 i already set up or if crossover I is locked normal by a train insection IT, in which case relay INWK will be picked up to open thecircuit for route 48, or the secondary route may be selected manually.By reference to Fig. 6 it will be seen that each relay WR will becomeenergized in its normal or reverse direction, provided the associatedlocking relay LR is picked up, by operating the corresponding individualswitch lever such as IL to the left or right, respectively from thecenter position shown. That is, crossover I may be operated to normal topick up relay INWK, or crossover 5 may be operated to reverse to pick uprelay ERWK by means of the individual levers IL and EL, respectively, inwhich case back contacts of these relays will open the route circuitsfor the preferred route 4-I0 via 1 reversed and thereby permit theselection of the secondary route 4II via 5 reversed.

In the foregoing I have considered only the establishment of routes fortraffic movements from left to right. For trainc movements in theopposite direction the operations are generally similar except that thelower wire of the route circuit is the one that is energized first andfor the intermediate signal location relay SANW is operated in place ofrelays 8XR, 8X8 and BPS. Considering route Iil2, for example, relay IOPSpicks up in response to the operation of button IOP as an entrancebutton, closing a connection to terminal B at its front contact II! topick up relays IANW and SANW to extend the circuit for route IlI2 tocontact II8 of button 2P, the closing of contact I I8 completing theselection of route Ifl-2 by the energization of relays IANE It is clear,therefore, that route and BANE, relay IBHR being energized over theconnection to terminal I3. Similarly, for. the main line route I2--4, ifrelay I2PS is picked up by operating button IZP a connection to terminalB at front contact 49 of relay I2PS provides for the energization ofrelays SBNW and IBNW, whereupon button 4P may be operated to pick uprelays 3NE and IBNE, relay I2HR being energized over the connection toterminal I4.

The circuits for relay I RW in Fig. 1A illustrate the principle ofselection employed when there are two alternative routes such a theroutes I04 via I reversed and I04 via 5 reversed. If relay IIIPS ispicked up to connect terminal B at contact III to the route circuits forboth of these routes, relay IRW, associated with the circuit for thepreferred route I04 via I reversed, will be picked up over front contactII9 of relay IANW to open the circuit for relay IBNW which otherwisewould become energized over the circuit for the secondary route Ill-4via 5 reversed. Relay IRE will then pick up in response to the operationof the exit button 4P to effect the selection of the preferred route.If, however, for any reason relay IBNW picks up in place of relay IRW,the operation of the exit button 4P will cause relay 3NE to pick up toeffect the selection of the secondary route. The back contacts I20 andI2I of relays IBNW and 3NE in parallel in the circuit for relay IRW areboth open when the secondary route Iii-4 via 5 reversed has been fullyselected and prevent relay lRW from becoming energized to interfere withthe circuits for that route. It will be seen that relay IRW may bepicked up not only when point I0 is the entrance point and relay IANW ispicked up, as above described, but also when point 4 is the entrancepoint and relay IRE is picked up first to close it contact 92 asrequired for setting up route 48, and in addition, if the reverseindication relays 'IRWK and IRWK are both picked up to close theircontacts I22 and $23. The last-mentioned branch circuit provides a meansfor manually establishing the run-around route I2 I.

To set up this run-around route I24 via I reversed and I reversed, theoperator first moves levers "IL and IL of Fig. 6 to their right-handpositions, whereby crossovers I and I are reversed individually andtheir indication relays 'IRWK and IRWK picked up. The route button I2Pand 4.? are then operated in that order. The open back contacts of therelays 'IRWK and IRWK in the route circuit for the main line route i24prevent the completion of that circuit, while their front contacts I22and I23 now closed permit relay IRW to pick up to complete the routecircuit for the run-around route.

By reference to Fig. 10 it will be seen that the route circuit inquestion can be completed only if the lower wire is energized first forthe reason that the only available circuit for energizing relay IRE inresponse to an operation of button 4P is the one including a frontcontact of relay 'IRW.

In other words, this run-around route circuit is directional and cannotbe set up by operating the route buttons I2P and 4P in the reverseorder.

The individual switch levers as shown in Fig. 6 are arranged so thatthey are ineffective unless they are operated at a time when the trackswitches they control are free to respond. This is accomplished as inthe Young Patent No. 2,179,462, issued November 7, 1939, for Railwaytraffic controlling apparatus. by the provision of a center contact oneach lever which, as will be clear from th drawing, must be closed inorder to pick up the associated locking relay LR.

Considering next the secondary route [-4 via reversed, it will be seenthat this route, like the corresponding one for the opposite direction,may be selected in place of the preferred route Ill-4 via I reversed, byindividual switch lever operation, either by operating cross-over lnormal to pick up relay INWK or by operating cross-over 5 to reverse topick up relay ERWK. Furthermore, since these indication relays arecontrolled by the locking relays and hence by the track relays, thissecondary route will be selected automatically in response to theoperation of buttons IBP and 4? in case, for example, route 2-8 isoccupied or if crossover 5 is reversed and section ST is occupied.

In the foregoing I have described a novel system of route selectioninvolving a route button and associated stick relay for each route endand a single route circuit for each available route extending betweenthe two ends of the track layout over branches of which a route relayfor each switch of the route may be energized to thereby establish theroute regardless of the order of operation of two route buttonsidentifying its opposite ends, and in which a signal control relay isenergized over another branch of the same route circuit to automaticallyclear the signal governing traflic movements over the route thusestablished in one direction or the other, dependent only upon therelative order of operation of the route buttons. I have also pointedout a number of ways in which this arrangement may be varied to suitparticular requirements. For example, I have shown how a route may berendered available only when the route buttons are operated in aparticular order, or by positioning one or more of the track switches byindividual lever operation prior to the operation of the route buttons,or in the event a preferred alternative route is unavailable. Inaddition, I have shown how partial routes involving an intermediatesignal may be provided for either with or without the operation of anintermediate route button.

Although a relatively simple track layout has been used to illustrate myinvention, it is believed that in view of the description of thecircuits and operation as presented herein that my invention may bereadily applied by one skilled in the art to larger and more complicatedtrack layouts such as are often encountered in practice even though theymay differ widely from the layout shown herein.

Although I have herein shown and described only one form of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In an interlocking control system, a track layout including trackswitches adapted to form different traffic routes, a route button foreach route end, a normal and a reverse route relay for each trackswitch, a route circuit network of conductor portions arranged toprovide energizing circuits for the route relays and to be connected endto end over front contacts of such route relays to form route circuits,there being one such circuit for each available route through the tracklayout, each route circuit comprising two conductors extending fromcontacts associated with the route button for one end to contactsassociated with the route button for the other end of the correspondingroute so arranged that the route relays for the switches of any routewhich face in opposite directions are energized over differentconductors, means normally responsive to the momentary operation of theroute button for the entrance end of a desired route to connect a sourceof current to one conductor of the route circuit for such route at thatend thereby successively energizing one route relay for each trailedswitch in such route, means for maintaining said source of currentconnected to said one conductor until the route is cancelled, meansresponsive to the subsequent momentary operation of the route button forthe exit end of the desired route to extend the connection of saidsource of current to the other conductor of the same route circuit atthat end thereby successively energizing one route relay for each facingswitch of said route, means controlled by one of the route relaysenergized over said other conductor for maintaining the connectionbetween the two conductors of the energized route circuit until saidroute is cancelled, and means controlled by the energized route relaysfor operating the track switches to corresponding normal or reversepositions as required for the desired route.

2. In an interlocking control system, a track layout including trackswitches adapted to form different trafiic routes, a route button havingtwo normally open contacts for each route end, an entrance relay foreach route button, a normal and a reverse route relay for each trackswitch, a route circuit network of conductor portions arranged toprovide energizing circuits for the route relays and to be connected endto end over front contacts of such route relays to form route circuits,there being one such circuit for each available route through the tracklayout, each route circuit comprising two conductors over which theroute relays for switches facing in opposite directions may beseparately energized, each conductor being connected at each end overback contacts of the entrance relay for the corresponding route end toone normally open contact of the associated route button, means normallyeffective to energize each entrance relay in response to the operationof the associated route button comprising a circuit including the othernormally open contact of said button to thereby disconnect the twoconductors of the adjacent route circuit end from said one contact ofthe operated route button, means comprising a front contact of theenergized entrance relay for supplying current to one conductor only ofthe route circuit connected thereto to successively energize one routerelay for each trailed switch of the desired route, thereby extendingthe connection of said source of current to the one contact of the routebutton for the exit end of such route, means including a back contact ofone of the energized route relays for preventing the energization of theentrance relay associated with the route button for the exit end of thedesired route thereby rendering the operation of such button effectiveto extend the connection of said source of current to the otherconductor of the adjacent route circuit end to successively energize oneroute relay for each facing switch of the .desired route, meansincluding back contacts of the energized route relays for isolating theconductors over which they are controlled for those of conflicting routecircuits, and circuits including front contacts of the energized routerelays for operating the track switches to corresponding normal orreverse positions as required for the desired route.

3. In an interlocking control system, a track layout including trackswitches adapted to form different traffic routes, a route button havingtwo normally open contacts and a normally closed contact for each routeend, an entrance stick relay for each entrance button, a normal and areverse route relay for each track switch, a route circuit network ofconductor portions arranged to provide energizing circuits for the routerelays and to be connected end to end over front contacts of such routerelays to form route circuits, there being one such circuit for eachavailable route through the track layout, each route circuit comprisingtwo conductors extending at each end over back contacts of the entrancerelay for the corresponding route end to one normally open contact ofthe associated route button, the route relays for the switches of anyroute which face in opposite directions being energized over differentconductors, a circuit closed in response to the operation of the routebutton for the entrance end of a desired route if such route isavailable, including its other normally open contact for picking up theassociated entrance stick relay to thereby disconnect the two conductorsof the adjacent route circuit end from said one contact of the operatedroute button, a stick circuit for each entrance stick relay includingits own front contact and the normally closed contact of the associatedroute button, means including a front contact of the energized entrancestick relay for connecting a source of current to one conductor only ofthe route circuit for the desired route to successively energize oneroute relay for each trailed switch of the desired route, therebyextending the connection of said source of current to the one contact ofthe route button for the exit end of such route, means including a backcontact of one of the energized route relays for preventing theenergization of the entrance stick relay associated with the routebutton for the exit end of the desired route thereby rendering theoperation of such button effective to extend the connection of saidsource of current to the other conductor of the adjacent route circuitend to successively energize one route relay for each facing switch ofthe desired route, means including a front contact of one of the routerelays energized over said other conductor for maintaining theconnection between the two conductors, means including back contacts ofthe energized route relays for isolating the conductors over which theyare controlled from those of conflicting route circuits, and circuitsincluding front contacts of the energized route relays for operating thetrack switches to corresponding normal or reverse positions as requiredfor the desired route.

4. In an interlocking control system, a track layout including trackswitches adapted to be interconnected to form different traffic routes,signals at the ends of the routes for governing traffic movementsthrough the track layout in opposite directions, a route button for eachsignal location, a normal and a reverse route relay for each trackswitch, energizing circuits for the route relays comprising routecircuit portions conforming to the track portions which are adapted tobe interconnected over front contacts of the route relays to form routecircuits over which the route relays for theswitches of a route may besuccessively energized, there being one route circuit for each availableroute through the track layout, each route circuit comprising twoconductors over which the route relays for the switches trailed foropposite directions of traffic movement may be separately energized,means including back contacts of the route relays for isolating theroute circuits over which they are energized from other route circuits,means normally responsive to the momentary operation of the route buttonfor either end of an available route to connect a source of current to aroute circuit conductor terminating at that end to effect theenergization of a route relay for each switch which may be trailed by atrain entering the layout at the corresponding route end, the energizedroute relays being effective to isolate the route circuits for theseroutes from those having different entrance ends at the same end of thelayout, means responsive to the momentary operation of the route buttonfor either end of an available route when one conductor of a routecircuit terminating at the corresponding point is already connected to asource of current at its opposite end to extend said connection to theother conductor of the same route circuit to effect the energization ofone route relay for each remaining switch of the desired route, theroute relays thereby energized being effective to isolate the routecircuit for that route from those having different exit ends, and meanscontrolled by the energized route relays for operating the trackswitches to normal or reverse positions as required for the desiredroute and for clearing the signal at one end or the other of such routewhen such route is established depending upon the relative order ofoperation of the route buttons for the opposite ends of such route.

5. In an interlocking control system according to claim 4, in which theroutes established by the operation of the route relays are availablefor trafiic movements in either direction, means for rendering aparticular route establishable for traffic movements in one directiononly, comprising a connection over which one route relay for a switch ofsaid particular route is energized when current is supplied to oneconductor of the route circuit for said route, which includes one ormore normally open contacts in multiple one of which is a front contactof a route relay controlled over the other conductor of the routecircuit for said particular route, said one front contact being bridgedby another contact if the energization of said one route relay isrequired in order to establish a different route.

6. An interlocking control system for controlling the operation of poweroperated track switches adapted to form different traffic routes in twodirections through a track layout, comprising manually operable entranceand exit contacts for each route end, an entrance stick relay for eachroute entrance having a pick-up circuit contact at its other end, meanscomprising back contacts of the route relays for each route forisolating the directional circuits for such route from those forconflicting routes, means responsive to the closing of the entrancecontact for the entrance end of an available route for energizing theassociated entrance relay, means including a front contact of thatentrance relay for supplying current to the entrance end of onedirectional circuit for such route to thereby energize one route relayfor each trailed switch of such route, and to extend the energization ofsuch circuit to its exit end, means responsive to the subsequent closingof the exit contact for the exit end of such route for supplying currentfrom the directional circuit already energized at its exit end to theadjacent entrance end of the other directional circuit for the sameroute thereby energizing one route relay for each facing switch in suchroute, and switch control relays controlled directly by the energizedroute relays for operating the track switches to the positions requiredfor such route.

7. An interlocking control system according to claim 6, in which thepick-up circuit for each entrance relay includes back contacts of one orboth route relays for a switch located in the routes having thecorresponding entrance end, said route relays having energizing circuitsincluding front contacts of the entrance relays for the opposite end ofsuch routes.

8. An interlocking control system according to claim 6, in which theclosing of the exit contact for the end of any route establishes aconnection between the two directional circuits for such route over backcontacts of the entrance relay for the exit end of such route toenergize the route relays in one of said circuits by current supplied tothe other directional circuit for the same route over a front contact ofthe entrance relay at the opposite end of said other directional circuitand in which a front contact of one of the route relays which picks upin response to the closing of said exit contact maintains the connectionbetween the two directional circuits for the same route after said exitcontact is opened.

9. An interlocking control system according to claim 6, in which backcontacts controlled by that route relay which governs the conflictingposition of a track switch located adjacent the entrance end of a routeand occupying a trailing position with respect to the correspondingtraific direction are located in the circuit for the correspondingentrance relay instead of in the circuit for the adjacent route relaywhich such entrance relay controls when energized.

10. An interlocking control system according to claim 6, in which agiven route is normally unestablishable, a normally inactive switchlever for a switch in said given route, means for operating said switchindividually to normal or reverse in response to the movement of saidlever from an inactive position to the corresponding normal or reverseposition, a normal and a reverse indication relay for said switch, meansfor energizing the corresponding normal or reverse indication relay whenthe switch assumes the position to which it is operated by said lever,and means for rendering said given route establishable in response tothe operation of the entrance and exit contacts for its opposite ends,comprising a route circuit corresponding to said route including a frontcontact of that normal or reverse indication relay which becomesenergized when, said switch is individually operated to the positionrequired for thegiven route.

11. In an interlocking control system, a track layout including trackswitches adapted to form different traflic routes, a route button foreach route end, a normal and a reverse route relay for each track switchfor governing its operation to a corresponding position, normallyinactive individual switch levers for operating the track switches tonormal or reverse, normal and reverse indication relays for the trackswitches, means for energizing the normal or reverse indication relayfor each track switch when it assumes the corresponding normal orreverse position in response to the operation of its individual switchlever, a route circuit network including a route circuit for eachavailable route through the track layout each route circuit controllingthat route relay for each switch of the corresponding route whichgoverns the switch to the position required for that route, each routecircuit also including a back contact of that indication relay for eachswitch of the corresponding route which becomes energized when thatswitch is individually operated to a conflicting position, meansresponsive to the successive operation of the two route buttons for theopposite ends of any route to supply current to the route circuit forsuch route to efiect the energization of one route relay for each switchof the route but only if the indication relay contacts in such routecircuit are closed, and switch control relays controlled directly by theenergized route relays for operating the track switches to the positionsrequired for such route.

12. In an interlocking control system, a track layout including trackswitches adapted to form different traffic routes, a route button foreach route end, a normal and a reverse route relay for each trackswitch, locking relays for the switches each of which is energized onlywhen conditions are proper for operating the corresponding switchcircuits including front contacts of the route relays and of theassociated locking relays for eifecting the operation of the trackswitches to normal or reverse, normal and reverse indication relays forthe track switches, means for energizing the normal or reverseindication relay for each track switch when the corresponding normal orreverse route relay is energized and the switch assumes the position towhich it is operated by such route relay, a route circuit networkincluding a route circuit for each available route through the tracklayout each route circuit controlling one route relay for each switch ofthe corresponding route for governing the switch to the positionrequired for that route, each route circuit also including a backcontact of that indication relay for each switch of the correspondingroute which becomes energized when that switch is operated to aconflicting position, means responsive to the successive operation ofthe two route buttons for the opposite ends of any route to supplycurrent to the route circuit for such route to affect the energizationof one route relay for each switch of the route but only if theindication contacts in such route circuit are closed, and meansefiective if a looking relay becomes released when the normal or reverseindication relay for the corresponding switch is energized to maintainsuch indication relay energized as long as said locking relay remainsreleased.

13. In an interlocking control system, a track layout including'trackswitches adapted to form different tramc routes, signals at the ends ofthe routes for governing traffic movements through the track layout inopposite .directions, a route button for each signal location, a normaland .a reverse route relay for each track switch for governing itsoperation, a signal control relay for controlling each signal, 'acircuit network of interconnected route circuits including a distinctivecircuit for each route over which one normal or reverse route relay foreach track switch of such route and the signal control relay for thesignal at one end or the other of such route all successively energizedby current supplied to the circuit at the corresponding end, meansresponsive to the successive operation of the route buttons for theentrance and exit ends of a desired route to supply current to thecorresponding route circuit to successively energize one route relay foreach switch of such route and. to .prepare a circuit for that signalcontrol relay which controls the signal at the entrance end of suchroute, and means including indication contacts controlled by the trackswitches for completing said prepared circuit when the switches assumethe required positions as determined by the energized route relays toeffect the clearing of the signal at the entrance end of thecorresponding route.

14. An interlocking control system for selecting different trafficroutes through a track layout provided with power operated trackswitches, comprising polarized switch control relays for operating theswitches, an entrance and exit route button for each route .end, anormal and a reverse route relay for each track switch having frontcontacts for controlling the associated polarized relay, meansresponsive to the successive operation of the route buttons for theentrance and exit ends of any route to successively energize two seriesof route relays, those energized by the entrance button comprising onefor each trailed switch and those energized by-the exit buttoncomprising one for each facing switch in such route, and circuits foroperating each polarized switch control relay to normal or reverse asrequired to establish said route including said front contacts of thenormal or reverse route relay for the track switch which such polar-izedrelay controls, the circuit controlled by a particular route relay ofone series also including a front contact of an energized route relay ofthe other series which also controls another polarized relay associatedwith a different track switch in the same route.

15. An interlocking control system according to claim 14, in which thecircuit for operating one switch control relay to the required positionis controlled by one route relay only and that for operating another tothe required positionincludes in series, a front contact of a routerelay for the same track switch and a front contact of a route relay foranother track switch facing in the opposite direction in said route.

16. An interlocking control system according to claim 14, in which thecircuit for operating a particular switch control relay to one positionis controlled by one route relay only and that for operating the samecontrol relay to its other position includes in series, a front contactof the other route relay for the same track switch and a front contactof a route relay for another track switch facing in the oppositedirection in the same route.

' 17.- An interlocking control system according to claim 14, in whichthe circuits (for operating each of the two switch control relays whichcontrol adjoining track switches facing in opposite directions .in saidroute to positions to establish such route, include in series, frontcontacts of the route relays for both switches.

18. In an interlocking control systemaccording to claim 14, in which thepolarized control relay for a given track switch is operable todifferent positions to extend one or the other of two alternative routeshaving the same entrance end to a common exit end and the two routerelays for the given track switch are arranged to be supplied withcurrent from the same source, the circuit for each including a backcontact of the other; a circuit for operating the polarized relay to theposition required for one alternative route including a front contact ofone of said route relays, a circuit for operating the polarized relay tothe position required for the other alternative route including frontcon-' tacts of said other route relay and of a second route relay, saidsecond route relay being one which controls a second track switch insaid other alternative route, and means for bridging the back contact inthe circuit for said one route relay to render said one alternativeroute establishable when both are available, comprising a back contactof said second route relay.

19. In an interlocking control system, a track layout including twotracks connected by a pair of track switches to form a crossover routewhen reversed and parallel routes when normal, a polarized switchcontrol relay for controlling said track switches, a normal and areverse route relay for each track switch, two normal energizingcircuits for said switch control relay, one including a front contact ofone normal route relay and the other a front contact of the other normalroute relay, a reverse energizing circuit for said switch control relayincluding in series front contacts of both reverse route relays, meansfor selectively energizing said route relays to complete a circuit forsaid switch control relay, and means controlled by said switch controlrelay when energized for operating both track switches to normal orreverse.

20. In an interlocking control system, a track layout including twotracks connected by a pair of track switches to form a crossover routewhen reversed and parallel routes when normal, a polarized switchcontrol relay for controlling said track switches, a normal and areverse switch indication relay, an energizing circuit for eachindication relay closed when the polarized relay is energized in thecorresponding normal or reverse direction and the track switches are inthe corresponding normal or reverse position, a normal and a reverseroute relay for each track switch, manually controllable circuits forselectively energizing said route relays the circuit for each normalroute relay including back contacts ofthe reverse route and indicationrelays and the circuit for each reverse route relay including backcontacts of the normal route and indication relays, two circuits forenergizing said polar-' facing in opposite directions, a normal and areverse route relay for each switch, manually operable entrance and exitcontacts and an entrance relay for each signal location, circuits forselectively energizing said entrance relays each including theassociated entrance contact and a back contact of a route relay for aswitch occupying a facing direction for the corresponding trafiicdirection, a circuit for energizing one route relay for each switchwhich is in the trailing position for a given trailic direction in agiven route including a front contact of the corresponding entrancerelay, a pick-up circuit for one route relay for each facing switch insaid given route including said entrance relay front contact, a backcontact of the entrance relay for the opposite end of the route and theexit contact associated therewith, a holding circuit for one route relayfor each facing switch in said given route including front contacts ofone of said facing switch route relays and of said entrance relay, meanscontrolled by the energized route relays for operating the trackswitches of the given route to the positions required for said route andfor clearing the signal associated with the energized entrance relaywhen the switches assume such positions.

22. In an interlocking control system according to claim 21, in which asignal control relay is provided for each signal for governing itsoperation, and in which the signal control relays are controlled over aroute agreement circuit network including a circuit for each route eachof which includes the signal control relay for the signal at theentrance end of the route, a front contact of the associated entrancerelay, and normally open contacts which close when the track switches ofa route which such signal governs assume the positions to which they arecontrolled by the energized route relays, and means for supplying eachsuch circuit with current over a back contact of the entrance relay forthe exit end of the corresponding route, comprising a connection fromsuch back contact to the holding circuit for the facing switch routerelays established by the closing of the corresponding exit contact.

23. In an interlocking control system for the control of railway signalsgoverning trafiic movements in two directions through a track layout inwhich power operated track switches provide difierent traific routes,route buttons for the ends of the routes, a normal and a reverse routerelay for each track switch, an entrance relay for each signal location,a circuit for energizing each entrance relay controllable by theassociated route button, route circuits for the different routes eacharranged to be supplied with current over a front contact of theentrance relay associated with a route button which is operated todesignate the corresponding point as the entrance end of a desired routeto energize one route relay for each switch which occupies a trailingposition in any route having its entrance end at that point, meanscomprising back contacts of the route relays thereby energized forrendering the entrance relays for the opposite ends of such routesnon-responsive to the operation of their route buttons, means responsiveto the operation of a route button for the exit end of a route havingthose route relays picked up which its entrance relay controls forenergizing one route relay for each facing switch of such route over thesame route circuit, means including back contacts of the route relays inthat route circuit ior isolating it from route circuits for conflictingroutes, and means controlled by said energized route relays foroperating the track switches as required to establish the correspondingroute and to clear the signal associated with the energized entrancerelay when the switches assume such position.

24. In an interlocking control system according to claim 23, in which asignal is located at an intermediate point in a given route, a routebutton and an entrance relay being provided for controlling such signal,and in which the signal at one end of such route governs trafiicmovements in one direction over a first portion of the given routeextending only to said intermediate point, the signal at saidintermediate point governs trailic movements in the same direction overa second portion of said route extending to its opposite end, and thesignal at said opposite end governs traffic movements in the otherdirection over the entire route, a directional relay for each directionassociated with said intermediate point and controlled over the routecircuit for the given route, the energizing circuit for each directionalrelay including a front contact of the entrance relay for thecorresponding end of such route and a back contact of the otherdirectional relay, a circuit for controlling the entrance relay for eachend of the given route by the associated route button including a backcontact of the opposing directional relay, and a circuit for controllingthe entrance relay for the signal at said intermediate point in responseto the operation of its route button including back contacts of bothdirectional relays.

25. In an interlocking control system according to claim 23, in which asignal is located at an intermediate point in a given route, a routebutton and an entrance relay being provided for controlling such signal,and in which the signal at one end of such route governs trafficmovements in one direction over a first position of the given routeextending only to said intermediate point, the signal at saidintermediate point governs trafiic in the same direction over a secondportion of said route extending to its opposite end, and the signal atsaid opposite end governs trafiic movements in the other direction overthe entire route, a directional relay for each direction associated withsaid intermediate point and controlled over the route circuit for thegiven route, the energizing circuit for each directional relay includinga front contact of the entrance relay for the corresponding end of theroute and a back contact of the other directional relay, an exit stickrelay for said intermediate point only, a pick-up circuit for said exitstick relay including a first portion of the route circuit for the givenroute controlled directly by the entrance relay for the first portion ofsuch route and also including a back contact of the opposing directionalrelay and a normally open contact of said intermediate route button,means controlled by said exit relay when energized for sectionalizingthe route circurit at said intermediate point, means for holding saidexit stick relay energized over said first route circuit portion, meanscontrolled by said exit stick relay for completing the route circuit forthe first portion of the given route to effect the clearing of thesignal for governing traific movements over said first portion of thegiven route, a circuit for controlling the entrance relay for the signalat said intermediate point in response to the operation of its routebutton

